diff options
Diffstat (limited to 'Lib/test/test_datetime.py')
| -rw-r--r-- | Lib/test/test_datetime.py | 47 |
1 files changed, 27 insertions, 20 deletions
diff --git a/Lib/test/test_datetime.py b/Lib/test/test_datetime.py index a46e3cacad..8a8d315f9c 100644 --- a/Lib/test/test_datetime.py +++ b/Lib/test/test_datetime.py @@ -2561,8 +2561,10 @@ DAY = timedelta(days=1) # In the US, DST starts at 2am (standard time) on the first Sunday in April. DSTSTART = datetime(1, 4, 1, 2) # and ends at 2am (DST time; 1am standard time) on the last Sunday of Oct, -# which is the first Sunday on or after Oct 25. -DSTEND = datetime(1, 10, 25, 2) +# which is the first Sunday on or after Oct 25. Because we view 1:MM as +# being standard time on that day, there is no spelling in local time of +# the last hour of DST (that's 1:MM DST, but 1:MM is taken as standard time). +DSTEND = datetime(1, 10, 25, 1) class USTimeZone(tzinfo): @@ -2616,9 +2618,9 @@ utc_real = FixedOffset(0, "UTC", 0) utc_fake = FixedOffset(-12*60, "UTCfake", 0) class TestTimezoneConversions(unittest.TestCase): - # The DST switch times for 2002, in local time. + # The DST switch times for 2002, in std time. dston = datetime(2002, 4, 7, 2) - dstoff = datetime(2002, 10, 27, 2) + dstoff = datetime(2002, 10, 27, 1) theclass = datetime @@ -2656,25 +2658,25 @@ class TestTimezoneConversions(unittest.TestCase): # We're not in the redundant hour. self.assertEqual(dt, there_and_back) - # Because we have a redundant spelling when DST begins, - # there is (unforunately) an hour when DST ends that can't - # be spelled at all in local time. When DST ends, the - # clock jumps from 1:59:59 back to 1:00:00 again. The - # hour beginning then has no spelling in local time: - # 1:MM:SS is taken to be daylight time, and 2:MM:SS as - # standard time. The hour 1:MM:SS standard time == - # 2:MM:SS daylight time can't be expressed in local time. - # Nevertheless, we want conversion back from UTC to mimic - # the local clock's "repeat an hour" behavior. + # Because we have a redundant spelling when DST begins, there is + # (unforunately) an hour when DST ends that can't be spelled at all in + # local time. When DST ends, the clock jumps from 1:59 back to 1:00 + # again. The hour 1:MM DST has no spelling then: 1:MM is taken to be + # standard time. 1:MM DST == 0:MM EST, but 0:MM is taken to be + # daylight time. The hour 1:MM daylight == 0:MM standard can't be + # expressed in local time. Nevertheless, we want conversion back + # from UTC to mimic the local clock's "repeat an hour" behavior. nexthour_utc = asutc + HOUR nexthour_tz = nexthour_utc.astimezone(tz) - if dt.date() == dstoff.date() and dt.hour == 1: - # We're in the hour before DST ends. The hour after + if dt.date() == dstoff.date() and dt.hour == 0: + # We're in the hour before the last DST hour. The last DST hour # is ineffable. We want the conversion back to repeat 1:MM. - expected_diff = ZERO + self.assertEqual(nexthour_tz, dt.replace(hour=1)) + nexthour_utc += HOUR + nexthour_tz = nexthour_utc.astimezone(tz) + self.assertEqual(nexthour_tz, dt.replace(hour=1)) else: - expected_diff = HOUR - self.assertEqual(nexthour_tz - dt, expected_diff) + self.assertEqual(nexthour_tz - dt, HOUR) # Check a time that's outside DST. def checkoutside(self, dt, tz, utc): @@ -2687,6 +2689,11 @@ class TestTimezoneConversions(unittest.TestCase): def convert_between_tz_and_utc(self, tz, utc): dston = self.dston.replace(tzinfo=tz) + # Because 1:MM on the day DST ends is taken as being standard time, + # there is no spelling in tz for the last hour of daylight time. + # For purposes of the test, the last hour of DST is 0:MM, which is + # taken as being daylight time (and 1:MM is taken as being standard + # time). dstoff = self.dstoff.replace(tzinfo=tz) for delta in (timedelta(weeks=13), DAY, @@ -2759,7 +2766,7 @@ class TestTimezoneConversions(unittest.TestCase): # wall 0:MM 1:MM 1:MM 2:MM against these for utc in utc_real, utc_fake: for tz in Eastern, Pacific: - first_std_hour = self.dstoff - timedelta(hours=3) # 23:MM + first_std_hour = self.dstoff - timedelta(hours=2) # 23:MM # Convert that to UTC. first_std_hour -= tz.utcoffset(None) # Adjust for possibly fake UTC. |